Assessment of Recombination in the S-segment Genome of Crimean-Congo Hemorrhagic Fever Virus in Iran

Background: Crimean-Congo Hemorrhagic Fever Virus (CCHFV) belongs to genus Nairovirus and family Bunyaviridae. The main aim of this study was to investigate the extent of recombination in S-segment genome of CCHFV in Iran. Methods: Samples were isolated from Iranian patients and those available in GenBank, and analyzed by phyloge­netic and bootscan methods. Results: Through comparison of the phylogenetic trees based on full length sequences and partial fragments in the S-segment genome of CCHFV, genetic switch was evident, due to recombination event. Moreover, evidence of multi­ple recombination events was detected in query isolates when bootscan analysis was used by SimPlot software. Conclusion: Switch of different genomic regions between different strains by recombination could contribute to CCHFV diversification and evolution. The occurrence of recombination in CCHFV has a critical impact on epidemi­ological investigations and vaccine design

Crimean-Congo Hemorrhagic Fever in the One-Humped Camel (Camelus dromedarius) in East and Northeast of Iran

Background: This comprehensive study was conducted on multi-purpose one-humped camel (Camelus dromedarius) sera and ticks to assess the epidemiological aspects of the Crimean-Congo hemorrhagic fever virus (CCHFV) in northeast Iran. Methods: From May 2012 to January 2013, eleven cities were randomly selected in the Khorasan Provinces of Iran as “clusters,” and at least 14 one-humped camels were sampled from each area. Reverse transcriptase polymerase chain reaction was used for the detection of the CCHFV genome in ticks. Sera were analyzed using specific enzyme-linked immunosorbent assay tests. Results: Four hundred and eighty ixodid ticks were collected, and the genome of the CCHFV was detected in 49 (10.2%) out of 480 ticks. The CCHFV genome was detected in two out of four tick species, and in tick samples from three cities in Khorassan-e-Jonoobi. All three provinces, and six out of eleven cities, were CCHFV-specific IgG-positive. In total, nine (5.3%) out of 170 one-humped camels were IgG-positive. The highest rate of IgG-positive samples was found in Nehbandan (16.67%). Conclusion: Continued surveillance and strictly enforced importation and quarantine practices should be imple­mented to prevent human exposure and the on-going dispersal of infected ticks and livestock in these regions. It is recommended that acaricides be used to prevent CCHF transmission to humans, and to reduce the tick population. In addition, care should be taken by abattoirs workers and people who work with one-humped camels

Seroepidemiology and risk factors of Crimean-Congo Hemorrhagic Fever among butchers and slaughterhouse workers in southeastern Iran

Objective: Crimean-Congo Haemorrhagic Fever (CCHF) is a viral zoonotic disease. Butchers and slaughterhouse workers are considered to be high risk occupational groups for the disease. Sistan and Baluchistan province is an area in southeastern Iran which is endemic for CCHF, and the most confirmed cases of the disease are reported from this province. The aim of this study was to investigate the seroprevalence of CCHF and risk factors for seropositivity among them in Sistan and Baluchistan province in 2011. Methods: Questionnaire data and blood sample collection were carried out for each participant and the sera samples were sent to the national reference laboratory for ELISA IgG testing. Results: In this study, the seroprevalence of CCHF among 190 butchers and slaughterhouse workers from 11 counties was 16.49%. 79% of participants were aware that they were at risk of zoonosis and 39.7% did not use any personal protective equipment during their work. Of 31 CCHF IgG positive individuals in this study, eleven individuals had a previous record of CCHF infection in 57 months prior to the study. Conclusions: High seroprevalence of CCHF among butchers and slaughterhouse workers and minimal use of personal protective equipmentâs during daily work indicates the need for training courses, for these groups to increase their knowledge, attitude and practice with respect to zoonosis. Keywords: Seroepidemiology, Crimean-Congo Haemorrhagic Fever, Butchers, Slaughterhouse Workers, Ira

Surveillance of Rift Valley Fever in Iran between 2001 and 2011

Rift Valley fever virus (RVFV) is an acute zoonotic viral disease that mostly affects ruminants with an occasional spillover as human infection. Following the outbreak of RVF in Saudi Arabia in 2000, surveillance of both animal and human population in Iran increased until 2011. During this period 1206 ovine, 405 caprine, 325 bovine and 28 camel samples were tested for RVFV in nine provinces in Iran. None of these samples tested IgG positive. Moreover, amongst 37 clinically suspected human cases of patients with RVF symptoms, none of these samples tested positive for RVFV. Despite the fact that no positive cases in human or animal populations were identified in Iran, surveillance and monitoring of viral haemorrhagic fevers including RVFV will continue

Assessment of Recombination in the S-segment Genome of Crimean-Congo Hemorrhagic Fever Virus in Iran

Background: Crimean-Congo Hemorrhagic Fever Virus (CCHFV) belongs to genus Nairovirus and family Bunyaviridae. The main aim of this study was to investigate the extent of recombination in S-segment genome of CCHFV in Iran. Methods: Samples were isolated from Iranian patients and those available in GenBank, and analyzed by phyloge­netic and bootscan methods. Results: Through comparison of the phylogenetic trees based on full length sequences and partial fragments in the S-segment genome of CCHFV, genetic switch was evident, due to recombination event. Moreover, evidence of multi­ple recombination events was detected in query isolates when bootscan analysis was used by SimPlot software. Conclusion: Switch of different genomic regions between different strains by recombination could contribute to CCHFV diversification and evolution. The occurrence of recombination in CCHFV has a critical impact on epidemi­ological investigations and vaccine design.

Genetic Diversity of Crimean Congo Hemorrhagic Fever Virus Strains from Iran

Background: Crimean Congo hemorrhagic fever virus (CCHFV) is a member of the Bunyaviridae family and Nairovirus genus. It has a negative-sense, single stranded RNA genome approximately 19.2 kb, containing the Small, Medium, and Large segments. CCHFVs are relatively divergent in their genome sequence and grouped in seven distinct clades based on S-segment sequence analysis and six clades based on M-segment sequences. Our aim was to obtain new insights into the molecular epidemiology of CCHFV in Iran. Methods: We analyzed partial and complete nucleotide sequences of the S and M segments derived from 50 Iranian patients. The extracted RNA was amplified using one-step RT-PCR and then sequenced. The sequences were ana­lyzed using Mega5 software. Results: Phylogenetic analysis of partial S segment sequences demonstrated that clade IV-(Asia 1), clade IV-(Asia 2) and clade V-(Europe) accounted for 80 %, 4 % and 14 % of the circulating genomic variants of CCHFV in Iran respectively. However, one of the Iranian strains (Iran-Kerman/22) was associated with none of other sequences and formed a new clade (VII). The phylogenetic analysis of complete S-segment nucleotide sequences from selected Ira­nian CCHFV strains complemented with representative strains from GenBank revealed similar topology as partial sequences with eight major clusters. A partial M segment phylogeny positioned the Iranian strains in either associa­tion with clade III (Asia-Africa) or clade V (Europe). Conclusion: The phylogenetic analysis revealed subtle links between distant geographic locations, which we pro­pose might originate either from international livestock trade or from long-distance carriage of CCHFV by infected ticks via bird migration